u/blindedbydarkness

I had a mitigation system placed about 2 years ago in my basement. System is in an unfinished room. Readings still 8-12 in the room with the system(next to the sump pump). Readings vary 0.6-8.6 depending on time of year in the other parts of the basement which are finished and living spaces. Installer said the substrate was clay and that may alter efficiency of the system. I know we have numerous cracks and ways for radon to get in the house. But going back and trying to fix all of them would require a total gut to the finished parts. Do I add another system? Upgrade? Move? Get another installer to replace or fix?